Users with forward set receive duplicate messages at destination

Hello,

I have this problem with a new installation of Zimbra, that I am trying to solve for the last days, without success.
Everything is running smoothly, except for one thing: the accounts that have forward addresses configured receive duplicate messages at the destination every single time.

I tried everything and read thousands of articles on the Internet, without any luck.

Can anyone give me some advice please?
I can post every detail of the installation, just ask.

Would you like to describes what's the solution for the problem? Does this means apply the latest binary (currently zcs 8.0.3) fixed your issue or does this means editing /opt/zimbra/postfix/conf/master.cf.in for : -o receive_override_options=no_header_body_checks,no_ unknown_recipient_checks,no_address_mappings would be need for resolve the problem?